This invention relates generally to a durable product, and more particularly to a foldable product, and finds particular application as a patient aid device such as a walker, and a method of forming same. The invention is particularly applicable to a composite assembly for construction and use with foldable products of this type.
Walkers, in general are well known and are used to assist ambulation and provide additional stability for persons who are, for example, elderly, infirm, have a disability, or are in rehabilitation. Conventional walker designs have four legs in contact with the ground to provide stability, and yet are sufficiently light-weight for ease of use.
Traditionally, these walkers have been fabricated from light-weight hollow or tubular material such as steel, aluminum, etc. It is common to fabricate each side frame so that the first and second legs and a handle portion are formed from a single, unitary bent tubular member, i.e., the inverted U-shaped structure, where the terminal ends define first (front) and second (rear) legs of the structure and the bight portion defines the handle portion. Likewise, it is common to incorporate a handgrip, such as a PVC or closed cell foam pad, that is slid over and provided on a horizontal portion of the side frame assembly. Generally, the first and second side frame assemblies are joined by a front cross brace member(s).
It is also common to employ adjustable height legs that allow the height of the walker to be selectively increased or decreased for customized use. For example, each leg receives a sleeve member formed with a series of longitudinally spaced openings adapted to selectively register with similarly spaced openings formed in the lower ends of the legs. A spring-biased pin is mounted within the lower ends of the legs and biased outwardly through aligned openings in the legs and leg extensions to select the desired height of the adjustable leg. It is also common to mount rubber tips to the ends of the leg extensions to resist slipping and undesired movement.
Collapsible or folding walkers are also generally well-known in the art and fold in a compact manner so that the walker is easily stored or transported during travel. As previously noted, a front cross brace assembly typically spans and interconnects the first and second side frame assemblies. Again, it is common to use a light-weight metal tubular structure because of the desired strength and minimum weight as a cross brace member. Interconnection of the front cross brace member with the side frame assemblies, particularly in a foldable or selectively hinged arrangement, usually requires a large number of components. There is also an attendant cost associated with the labor-intensive steps to manufacture and assemble the foldable walker. For example, one or more metal tubes are bent along their length, and secured to first and second sleeves at opposite ends. Usually the ends of the tubes are notched and bell-mouthed to conform the ends to the sleeves. The sleeves are received over the front legs of respective side frame assemblies. It is necessary to rigidly and securely interconnect the cross brace to the sleeves, for example, through a welding or brazing operation.
A number of latch or locking mechanisms have been developed in the art to allow the side frame assemblies to pivot or rotate into a collapsed or storage position, and likewise to deploy into an open, locked position for use. The following list of patents is not intended to be exhaustive, but is representative of various locking mechanisms: U.S. Pat. Nos. 2,796,911; 3,658,079; 3,688,789; 3,690,652; 3,783,886; 3,993,088; 4,298,016; 4,518,002; 5,188,139; 5,201,333; 5,433,235; 5,529,425; and 5,853,219. As is evident in the prior art, the latching/locking mechanisms are formed from multiple components and thus are also expensive to manufacture and assemble the various components together.
More recently, foldable or collapsible walkers have been developed that incorporate plastic molded components into the assembly. For example, some have developed a plastic front cross brace member, while others additionally include molded side frame assemblies in conjunction with the front cross brace member. Representative patents include D373,555; U.S. Pat. Nos. 5,579,793; 5,862,825; and 6,014,981.
Even with these various designs, a trade-off exists among strength, weight, and cost to manufacture and assemble. Moreover, maintaining the features and benefits available in existing commercially available designs while trying to enhance the product design in one of the other areas is also a particular challenge. Accordingly, a need exists to develop a walker that requires fewer components to manufacture, sub-assemble, and assemble to yield a final product that can be produced at a much lower total cost, while still maintaining the benefits and features of known arrangements.